Post your modding questions here

[Nyarg]

It seems like if I don't fly far enough away the entities are deactivated but not activated again.

As I know server only keeps place and type destroyed entity.
Another current data (velocity, collision box, attach map etc) you must say to server via

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function eObj:get_staticdata()
   return minetest.serialize(self.p)   --- for self I keep all depend data in table
end

Then init again entity at

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function eObj:on_activate( staticdata)
   if staticdata == "" then   
      self.p = {}
      self.p.vel = {x=1,y=0,z=0}
   else
      self.p = minetest.deserialize(staticdata)
      self.object:setvelocity(self.p.vel)
   end
end

PS: on_activate = function(self, staticdata, dtime_s)
Wiki don't explain dtime_s in on_activate

[Nyarg]

I am stuck now because still, nothing shows up.

Why twice identical ?
function angledglass.register_glass(subname, recipeitem, groups, images, desc_glass, sounds)

Next give me error "attempt to index global "default" "
default.node_sound_glass_defaults())

After all I run main code as init.lua and finaly see

+ Spoiler

[GreenDimond]

n00b question: How do I make a tool break after 3 uses?
Thanks!

[TumeniNodes]

Why twice identical ?
function angledglass.register_glass(subname, recipeitem, groups, images, desc_glass, sounds)

Apparently because I didn't want it to work :P

Thank you very much Nyarg, much appreciated :D
A second pair of eyes is always the best solution

Now I have to look at the model and figure out why the 2 materials are not working as they should

[krokoschlange]

I want to make a tank mod and I need the rotation of a bone to add a another vector to it.
Because if if I do

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Code: Select all

self.object:get_bone_position("bone_name")

it returns two tables. How to get to the values of the second (rotation) table? What do I need instead of the x?:

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self.object:get_bone_position("bone_name").x

[Nyarg]

it returns two tables. How to get to the values of the second (rotation) table?

Where do you found get_bone_position() ?

Anyway as I think access will like (you may check it here https://www.lua.org/cgi-bin/demo)

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Code: Select all

t = {a = {11},b = {12}}
print(t.a[1])
print(t.b[1])

function fn()
   tt = {a = {21},b = {22},c = {x = 23,y = 24, z = 25}}
   ttt = {a = {31},b = {32},c = {x = 33,y = 34, z = 35}}
   return tt,ttt
end

print(fn().b[1])
print(fn().c.x)

v, w = fn()
print(w.c.x)


[krokoschlange]

Thanks I will try that. I found the function in the modding api.

[Nyarg]

I found the function in the modding api.

Oops it's right but wiki seems outdated now.

now I see get_bone_position() return separate table so look my previously post that I update now ) for separate table handling.

[krokoschlange]

Unfortunately I still don't get how to get a value from the second table like the 32

[orwell]

I want to make a tank mod and I need the rotation of a bone to add a another vector to it.
Because if if I do

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Code: Select all

self.object:get_bone_position("bone_name")

it returns two tables. How to get to the values of the second (rotation) table? What do I need instead of the x?:

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Code: Select all

self.object:get_bone_position("bone_name").x

Save in a local variable first:

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Code: Select all

local _, rot = self.object:get_bone_position("bone_name")
rot.x


Underscore as a placeholder variable that is discarded.

[orwell]

n00b question: How do I make a tool break after 3 uses?
Thanks!

uses=3 in tool capabilities!?
Or maybe it's 2 or 4, there was an issue with count being off by 1

[orwell]

I've got a very big problem. I'm not sure if this is the right place to post this but I'm not sure enough to open an issue.

To test I made this mod:

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minetest.register_entity(
   "eat:test1",
   {
      on_activate = function(self, staticdata, dtime_s)
         minetest.chat_send_all("<1> activated")
         minetest.chat_send_all("<1> "..dtime_s)
         if staticdata == nil then
            minetest.chat_send_all("<1> nil")
         elseif staticdata == "" then
            minetest.chat_send_all("<1> \"\"")
         else
            minetest.chat_send_all("<1> "..staticdata)
         end
         if not self.at then
            self.at = minetest.add_entity(self.object:getpos(), "eat:test2")
         end
         if self.at then
            self.at:set_attach(self.object, "", {x=0,y=1,z=1}, {x=0,y=0,z=0})
            minetest.chat_send_all("<1> attach")
         end
         self.object:setvelocity({x=1,y=0,z=0})
      end,

      get_staticdata = function(self)
         return "sta"
      end,
   }
)

minetest.register_entity(
   "eat:test2",
   {
      on_activate = function(self, staticdata, dtime_s)
         minetest.chat_send_all("<2> activated")
         minetest.chat_send_all("<2> "..dtime_s)
         if staticdata == nil then
            minetest.chat_send_all("<2> nil")
         elseif staticdata == "" then
            minetest.chat_send_all("<2> \"\"")
         else
            minetest.chat_send_all("<2> "..staticdata)
         end
         if staticdata ~= "" then
            if not self.object:get_attach() then
               minetest.chat_send_all("<2> remove")
               self.object:remove()
            end
         end
      end,

      get_staticdata = function(self)
         return "sta"
      end,
   }
)


entity-activation-test.zip

Entity2 should be always attached to entity1, even after de- and activation.
I spawned the entity and flew away and came again and watched what happens.
I'm pretty sure that something is wrong. I'm just not sure what exactly is wrong. The reason for this is that different things happen.
On join everything is ok.
Most of the times entity2 isn't attached for some reason.
It seems like if I don't fly far enough away the entities are deactivated but not activated again.
Try it out yourself and be confused like me.

Someone would need to rewrite all attachment code. There are many issues with it.
Some things you should know:
When objects get unloaded, attachments are lost. You need to reattach in the on_activate function.
Try this:
- Staff your second object (the attachee) with something unique, such as a concatenation of os.time()..os.clock()
(not that I am using this in advtrains....) and save that in staticdata
- In on_activate() of the first object (attacher) or inside step as long as not found, loop through minetest.luaentites and search for exactly that unique property. When found, attach that object.

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Code: Select all

attacher on_step()
....
if not self.has_attached then
  for aoid, luaentity in pairs(minetest.luaentities) do
    if luaentity.unique_id==id then
      local attachee=minetest.object_refs[aoid]
      self.object:set_attach(attachee, ....)
      self.has_attached=true
    end
  end
end

attachee on_activate(self,staticdata)
self.unique_id=staticdata
if self.unique_id=="" then
  self.unique_id=os.time()..os.clock()
end

attachee get_staticdata()
return self.unique_id


[DS-minetest]

@orwell: Thanks, marking the attachee could be an interesting idea. Nevertheless the attach is obscure.

[krokoschlange]

Save in a local variable first:

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Code: Select all

local _, rot = self.object:get_bone_position("bone_name")
rot.x


Underscore as a placeholder variable that is discarded.

Thank you, it works great!

[BrunoMine]

Hello guys.
I would like to develop a method to identify (in real time) the players that are close to a specific node.
I've put the code below:

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Code: Select all

local players = {}
minetest.register_abm{
   nodenames = {"mymod:mynode"},
   interval = 1,
   action = function(pos)
      local all_objects = minetest.get_objects_inside_radius(pos, 25)
      players = {}
      for _,obj in ipairs(all_objects) do
         if obj:is_player() then
            table.insert(players, obj)
         end
      end
      print(#players .. " players found")
   end,
}


My concern is, if this is really efficient.
I imagine there may be dozens of active nodes on a server, and this can lead to high processing usage.
Is there any better way to accomplish this task?
Does Minetest have any more suitable method for this?
Do not I have to worry about processing?

[Byakuren]

Hello guys.
I would like to develop a method to identify (in real time) the players that are close to a specific node.
I've put the code below:

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Code: Select all

local players = {}
minetest.register_abm{
   nodenames = {"mymod:mynode"},
   interval = 1,
   action = function(pos)
      local all_objects = minetest.get_objects_inside_radius(pos, 25)
      players = {}
      for _,obj in ipairs(all_objects) do
         if obj:is_player() then
            table.insert(players, obj)
         end
      end
      print(#players .. " players found")
   end,
}


My concern is, if this is really efficient.
I imagine there may be dozens of active nodes on a server, and this can lead to high processing usage.
Is there any better way to accomplish this task?
Does Minetest have any more suitable method for this?
Do not I have to worry about processing?

Instead of searching around each node for a player, use minetest.get_connected_players() and search for the node around each player. If you have a lot of nodes this will be faster, but I don't know exactly how many nodes you need for it to be faster. Probably you should try benchmarking it.

[DS-minetest]

@BrunoMine: #players doesn't work with such tables. Count the players in the for thing.

[ABJ]

How do I create something that runs as long as a block exists but disappears when it is dug? EG: smoke for fire.

[BrunoMine]

I am not able to use the dsdsds method. minetest.rollback_get_node_actions.

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Code: Select all

minetest.register_on_dignode(function(pos, oldnode, digger)
   local rollback = minetest.rollback_get_node_actions(
      pos, -- pos
      10, -- range
      5, -- seconds
      5 -- limit
   ) or {}
   
   minetest.chat_send_all(table.maxn(rollback).." actions")
end)


Results:

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Code: Select all

0 actions
0 actions
0 actions
...


What is wrong?

EDIT:
I forgot to enable it in minetest.conf
SOLVED!

[BrunoMine]

How do I create something that runs as long as a block exists but disappears when it is dug? EG: smoke for fire.

Have you tried an ABM?
This allows you to execute a function repeatedly while a node is active.

[DS-minetest]

How do I create something that runs as long as a block exists but disappears when it is dug? EG: smoke for fire.

Have you tried an ABM?
This allows you to execute a function repeatedly while a node is active.

An abm wouldn't make much sense here.
on_construct: Add a particlespawner in a variable (bla = minetest.add_particlespawner(particlespawner definition)) and store this variable somewhere, like in metadata.
on_destruct: Get this variable and remove the particlespawner again.
api:
particlespawner
on_construct and destruct

[burli]

The documentation says, that get_node_timer accepts fractional values. But this code doesn't work. I only get full seconds

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Code: Select all

minetest.get_node_timer(leaves_near[i]):start(math.random() * 10.0)

What's wrong? The documentation, the function or I?

[orwell]

The documentation, I think. Mesecons pressure plates also only work at an 1s interval.

[orwell]

How do I create something that runs as long as a block exists but disappears when it is dug? EG: smoke for fire.

Have you tried an ABM?
This allows you to execute a function repeatedly while a node is active.

An abm wouldn't make much sense here.
on_construct: Add a particlespawner in a variable (bla = minetest.add_particlespawner(particlespawner definition)) and store this variable somewhere, like in metadata.
on_destruct: Get this variable and remove the particlespawner again.
api:
particlespawner
on_construct and destruct

Particle spawners get removed when the block is unloaded I think. Use LBM to spawn it again.

[rubenwardy]

The documentation says, that get_node_timer accepts fractional values. But this code doesn't work. I only get full seconds

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Code: Select all

minetest.get_node_timer(leaves_near[i]):start(math.random() * 10.0)

What's wrong? The documentation, the function or I?

There's a setting which makes this run faster. By default it only runs once a second

[burli]

Ah, ok. Thanks

[GreenDimond]

How do I make items spawn in a certain area?
Explain:
I have block A and block B.
bA and bB form opposite corners of a cubic area.
I want a certain item to spawn anywhere in that area at a certain rate (appear and fall to the floor).
How do I do this (needs to be according to bA and BB so the area can be however I want)?

[ABJ]

How do I make something that gets created with a block and deleted with it?

[GreenDimond]

Another question: Is it possible to use items as buttons in a custom chest?
Explain:
Have a chest with 2 items.
Click/select an item and it takes you to another "page" in the chest.
In that "page", have a "back" item so when pressed takes you back to main "page".

[orwell]

You can add image buttons that look like the item. (item_image_button[])